Department of Internal Medicine, University of Oulu, Oulu, Finland.
Heart Rhythm. 2010;7(2):229-35. doi: 10.1016/j.hrthm.2009.11.004. Epub 2009 Nov 10.
Autonomic dysfunction tends to improve over time after acute myocardial infarction (MI), but the clinical significance of autonomic remodeling is not well known.
The purpose of this study was to test the hypothesis that the amount of recovery of autonomic function early after MI is associated with a risk for serious arrhythmias.
The prognostic significance of autonomic remodeling after MI was assessed in one post-MI cohort [Cardiac Arrhythmia and Risk Stratification after Myocardial Infarction (CARISMA)] and validated in a second cohort [Risk Estimation After Infarction, Noninvasive Evaluation (REFINE)]. Changes in heart rate variability (DeltaHRV) and heart rate turbulence (DeltaHRT) were measured from 24-hour ECG recordings performed early (5-21 days) and later (6 weeks) after MI in CARISMA (n = 312). DeltaHRV and DeltaHRT were similarly measured from early (2-4 weeks) and later (10-14 weeks) post-MI recordings in REFINE (n = 322).
HRV and HRT increased over time in both cohorts. Attenuated recovery of autonomic function, defined as DeltaHRT slope <2.0 ms/RR, was associated with a 9.4-fold (95% confidence interval 1.2-71.6; P = .03) higher risk of ECG-documented sustained ventricular tachycardia or ventricular fibrillation in CARISMA and a 7.0-fold (95% confidence interval 1.6-29.6; P = .009) higher risk of fatal or near-fatal events in REFINE. Changes in HRV and HRT were not predictive of nonarrhythmic death in either cohort.
Attenuated recovery of autonomic function early after MI consistently predicts a higher risk of fatal or near-fatal arrhythmic events. A lack of improvement in HRT early after MI appears to be a specific marker for serious arrhythmic events.
急性心肌梗死（MI）后，自主神经功能往往随时间逐渐改善，但自主神经重构的临床意义尚不清楚。
本研究旨在检验如下假设，即 MI 后早期自主功能恢复的程度与严重心律失常风险相关。
MI 后自主神经重构的预后意义在一项 MI 后队列研究（心肌梗死后心律失常和危险分层研究，即 CARISMA）中进行了评估，并在第二项队列研究（梗死后危险评估的无创性评估，即 REFINE）中进行了验证。在 CARISMA 中（n = 312），通过 24 小时心电图记录，测量 MI 后早期（5-21 天）和晚期（6 周）的心率变异性（DeltaHRV）和心率震荡（DeltaHRT）变化。在 REFINE 中（n = 322），通过早期（2-4 周）和晚期（10-14 周）MI 后记录，同样测量了 DeltaHRV 和 DeltaHRT。
在两个队列中，HRV 和 HRT 随时间逐渐增加。自主神经功能恢复减弱（定义为 DeltaHRT 斜率 <2.0 ms/RR）与 CARISMA 中 ECG 记录的持续性室性心动过速或心室颤动风险增加 9.4 倍（95%置信区间 1.2-71.6；P =.03），与 REFINE 中致命或近乎致命事件的风险增加 7.0 倍（95%置信区间 1.6-29.6；P =.009）相关。在两个队列中，HRV 和 HRT 的变化均不能预测非心律失常性死亡。
MI 后早期自主神经功能恢复减弱一致预测致命或近乎致命性心律失常事件风险增加。MI 后早期 HRT 改善不良似乎是严重心律失常事件的特异性标志物。
